Yup, you got it. I’ve run 6V6, 6L6, 6550, KT66, EL34, KT77 and KT88’s in it. Its super versatile that way. The chassis is a 5F2A that allows the tube swap, plus the cathode bypass options for different voicing. Its pretty brilliant.
There is a small chart in the book that describes how to wire the impedance switch. I have a small printout that can be used to attach to the cabinet to remind you what direction works for what tubes here: